Screen process printing frame having means for removing staples therefrom



Dec. 24, 1963 J. J. ANDRUS 3,115,093

SCREEN PROCESS PRINTING FRAME HAVING MEANS FOR REMOVING STAPLES THEREFROM Filed March 22, 1962 FIG.|

6 Strip 1 x2 INVENTOR JULIUS J. ANDRUS ATTOR United States Patent O 3,115,093 SCREEN PROCESS PRINTING FRAME HAVENG MEANS FOR REMOWNG STAPLES THEREFROM Julius J. Andrus, Scotch Plains, N.J., assignor to Azoplate Corporation, Murray Hill, NJ., a corporation of New Jersey Filed Mar. 22, 1%2, Ser. No. 181,532 2 Claims. (Cl. Mil-427.1)

This invention relates to a method for removing a plurality of staples rapidly and conveniently from a work piece and, more particularly, from a workpiece of the type which is repeatedly used.

The invention will be illustrated in connection with screens for use in the screen printing process although it is not restricted thereto. In the screen printing process, a highly porous carrier material, usually a screen, made of synthetic or natural fibers or metal is stretched on a frame and secured there to by means of a plurality of staples passing through the screen and into the frame. The screen is coated with a colloid solution containing a sensitizer, and the coating operation is performed in such a manner that the coating solution fills the screen meshes without the formation of pin holes in the coating.

After drying the coating, it is exposed to light under a master, whereby the colloid is hardened in those portions of the layer struck by light. The hardening is proportional to the degree of transparency of the master. On those portions of the coating not struck by light, the colloid layer remains soluble and is removed, for example, by a water spray; the developernent results in opening of the carrier pores in those portions not struck by light so that in the subsequent printing process the ink or dye can be forced, by means of a squeegee, through these openings onto the material to be printed, in a pattern corresponding to the master used.

A tedious procedure which is necessary before attaching a new silk or nylon screen to the wooden printing frame is the removal of the staples used to hold down the previous screen. About 60 stables are used to hold down an 8 inch by 5 inch silk or nylon screen in a wooden frame having external dimensions of 11 inches by 8 inches. Prior to the present invention, it was necessary to remove these staples individually, using a screw driver or a strong spatula. Some users allow the staples to accumulate and, after the frame has been used approximately six times, all the staples are removed before a new screen is attached to the frame but each staple must be individually removed.

The present invention provides a method whereby the staples may be removed from a printing frame or other workpiece by a single action in less than a second. In the present invention, a strip of material is placed intermediate the staples and the screen printing frame with the staples passing through both the strip of material and the process screen. When it is desired to change the screen, all that is necessary is to pull on the strip of material and all of the staples are removed quickly and easily from the frame without the necessity for the individual removal thereof.

Referring to the accompanying drawings, FiGU-RE 1 is a perspective view showing the removal of a plurality of staples from a screen printing frame and FIGURE 2 is a plan View of a screen printing frame showing the placement of four strips of material overlying the sides of the frame with the stables securing the screen passing therethrough.

Referring to FIGURE 1 of the drawings, the printing frame, generally made of wood, has the sides 2 and 4 and a printing screen 6 secured thereto by means of a plurality of staples 8. The staples are passed through a strlp ice of material 10 which may be of metal, plastic, or any other material having suflicient strength so that the staples do not remain embedded in the woden frame when the end 12 of the strip is raised as shown in the drawings. One strip of material is used on each side of the frame and a pull tab is left unstapled at one end of each strip, as shown at 14, in order to facilitate the removal of the strip and the staples secured thereto. The staples may be passed the strip 10, the screen -6 and into the frame by means of a conventional stapling gun. -It is immaterial whether strip 10 overlies the screen 6 or is placed between the screen 6 and the wooden frame 2 since the staples are removed easily and quickly in either case.

In FIGURE 2 of the drawings, an illustration is given of the placement of four strips of material on a fourside printing frame, the frame having the sides 16, '18, 2t] and 22. On side 16, a strip designated as strip 1 in the drawings, is first staple to the frame, either over or under a printing screen, not shown. A portion 24 of strip 1 is not staple in order to provide a means for gripping the strip and removing it from the frame. After strip 1 is stapled in the frame, strip 2 is similarly stapled to side 20 of the frame leaving the portion 26 unstapled to provide a pull tab. Strip 3 is then staple to side 22 of the frame leaving the portion 28 unstaple and overlapping a portion of strip 1 whereby a pull tab is provided. Strip 4 is similarly staple to side 18 of the frame, leaving a portion 30 thereof unstaple and overlapping strip 2. The strips are removed from the frame in the reverse order from that in which they are applied.

Removal of each strip with the adhering staples requires less than a second. The shorter strips lift about 1 to 13 staples each, and the longer strips remove from 17 to 21 staples each, using strips of aluminum having a thickness of at least about 0.001 inch.

The strips must be made of a material having sufiicient strength so that the staples do not remain embedded in the wood frame. Ordinary cardboard was not found to be suitable for this purpose and aluminum of a thickness less than about 0.001 inch was also found to have insufficient strength, as a number of the staples pulled through the strip. However, using aluminum having a thickness of at least 0.011 inch resulted in an entirely satisfactory article as the staples penetrated the aluminum and the wood frame without distorting and were completely removed merely by raising the strip.

The use of an aluminum strip is not inconvenient to the operator as it is simply laid over the stretched silk or nylon and the like. When the aluminum strip was placed between the silk and the wood, the silk tore slightly where several of the staples penetrated, but this is normal without the use of the aluminum strip and occurred to no greater extent than usual. Placing the aluminum strip over the screen prior to stapling tended to prevent the normal tearing of the screen as the strip acted as a protector for the screen.

While the invention has been illustrated in connection with the securing of screens to screen process printing frames, it obviously is not restricted thereto and can be utilized in any operation where it is necessary to remone a plurality of stables from a base material.

It will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.

What is claimed is:

1. An assembly for use in screen process printing comprising a frame, an aluminum strip having a thickness of at least 0.001 inch overlying each side of the frame and overlapping an adjacent strip at one end thereof, and a 3 4 plurality of staples passing through a process screen and References Cited in the file of this patent the alummum Stnps mto the frame except the over Kosloff: The Art and Craft of Screen Process Printing,

lapping portions of the strips. 1960 Th B P r 2. An assembly according to claim 1 in which the screen pp. gg a i fi ggfigf Mllwaulee only is intermediate the aluminum strips and the frame.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,115,093 December 24, 1963 Julius J. Andrus It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 9, after "passed" insert through line 11, after "whether" insert the lines 18, 20, 24 and 27, for "staple", each occurrence, read stapled lines 25 and 28, for "unstaple", each occurrence, read unstapled same column 2, line 70, for "00001" read 0,011

Signed and sealed this 5th day of May 19641o EAL) .test:

NEST W. SWIDER EDWARD J. BRENNER testing Officer Commissioner of Patents 

1. AN ASSEMBLY FOR USE IN SCREEN PROCESS PRINTING COMPRISING A FRAME, AN ALUMINUM STRIP HAVING A THICKNESS OF AT LEAST 0.001 INCH OVERLYING EACH SIDE OF THE FRAME AND OVERLAPPING AN ADJACENT STRIP AT ONE END THEREOF, AND A 